A Long-term Follow-up Study to Evaluate the Safety and Efficacy of RGX-501

This long-term observational study is designed to follow subjects who, during another Clinical Study, received gene therapy treatment used to treat their Homozygous Familial Hypercholesterolemia (HoFH) disease. This study is intended to follow those subjects for up to 5 years since they received treatment to look for any long-term safety concerns. There is no investigational drug or therapy provided as part of this study.

Study Overview

• Status: Active, not recruiting
• Conditions: Homozygous Familial Hypercholesterolemia (HoFH)
• Intervention / Treatment: Drug: Single intravenous (IV) dose of human Low Density Lipoprotein Receptor (LDLR) Gene Therapy

Detailed Description

Homozygous Familial Hypercholesterolemia (HoFH) is a rare genetic metabolic disorder characterized by absent or severely reduced capacity to catabolize circulating LDL particles by the hepatic LDL receptor. As a consequence, HoFH subjects present abnormal total plasma cholesterol (LDL-C) levels, resulting in severe atherosclerosis often leading to early onset of cardiovascular disease. Early initiation of aggressive treatment for these patients is therefore essential. Unfortunately, despite existing therapies, treated LDL-C levels could remain well above acceptable levels. Thus, the functional replacement of the defective LDLR via AAV-based liver-directed gene therapy, RGX-501, may be a viable approach to treat this disease and improve response to current lipid-lowering treatments.

This is a prospective, observational study to evaluate the long-term safety and efficacy after a single administration of RGX-501. Eligible participants are those who previously have enrolled in a clinical study and received a single intravenous infusion of RGX-501.

• Study Type: Observational
• Enrollment (Actual): 8

Contacts and Locations

Study Locations

• Canada
  • Quebec
    • Montreal, Quebec, Canada, H1T1C8
      • Montreal location
• Netherlands
  • Rotterdam, Netherlands, 3015 CE
    • Rotterdam location
• United States
  • Ohio
    • Columbus, Ohio, United States, 43210
      • Columbus Location
  • Oregon
    • Portland, Oregon, United States, 97239
      • Portland location
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19104
      • Philadelphia Location
  • Tennessee
    • Nashville, Tennessee, United States, 37232
      • Nashville Location

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Participants who have previously received RGX-501 in a separate parent trial

Description

Inclusion Criteria:

• To be eligible to participate in this study, a participant must have previously received RGX-501 in a separate parent trial, and the participant or participant's legal guardian(s) is/(are) willing and able to provide written, signed informed consent after the nature of the study has been explained, prior to any research-related procedures.

Exclusion Criteria:

• None

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
RGX-501; Study participants who have received RGX-501 gene therapy in a separate parent trial	Drug: Single intravenous (IV) dose of human Low Density Lipoprotein Receptor (LDLR) Gene Therapy; No investigational product will be administered in this study. All participants have previously received a one-time intravenous infusion of RGX-501 in a separate clinical trial; Other Names: RGX-501

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of incidents of new and unexpected adverse events and serious adverse events.	The number of times a new and unexpected adverse event and/or serious adverse event is reported.	Up to 5 years after receiving treatment with RGX-501

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The absolute LDL-C level in mg/dL by beta quantification	Absolute LDL-C level by beta quantification at Year 3 after receiving treatment with RGX-501	Year 3 after receiving treatment with RGX-501
Absolute total cholesterol, LDL-C, very low density lipoprotein cholesterol (VLDL-C), high density lipoprotein cholesterol (HDL-C), calculated non-HDL-C, triglycerides (TG), and lipoprotein a (Lp(a)) over the study duration	Absolute total cholesterol, LDL-C, very low density lipoprotein cholesterol (VLDL-C), high density lipoprotein cholesterol (HDL-C), calculated non-HDL-C, triglycerides (TG), and lipoprotein a (Lp(a)) over the study duration	Up to 5 years after receiving treatment with RGX-501
Usage of lipid-lowering therapies over time	Usage of lipid-lowering therapies over time	Up to 5 years after receiving treatment with RGX-501

Collaborators and Investigators

• Sponsor: REGENXBIO Inc.

Study record dates

Study Major Dates

• Study Start (Actual): September 30, 2019
• Primary Completion (Anticipated): September 29, 2024
• Study Completion (Anticipated): September 29, 2025

Study Registration Dates

• First Submitted: September 3, 2019
• First Submitted That Met QC Criteria: September 3, 2019
• First Posted (Actual): September 6, 2019

Study Record Updates

• Last Update Posted (Estimate): March 9, 2023
• Last Update Submitted That Met QC Criteria: March 8, 2023
• Last Verified: March 1, 2023

More Information

Terms related to this study

• Keywords: Gene Therapy; Cardiovascular Disease; Atherosclerosis; Rare Diseases; Genetic Diseases; Metabolic Diseases; LDL Receptors
• Additional Relevant MeSH Terms: Metabolic Diseases; Genetic Diseases, Inborn; Metabolism, Inborn Errors; Lipid Metabolism Disorders; Hyperlipidemias; Dyslipidemias; Lipid Metabolism, Inborn Errors; Hyperlipoproteinemias; Hypercholesterolemia; Hyperlipoproteinemia Type II
• Other Study ID Numbers: RGX-501-102

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No